In the case of a headlamp having a discharge light source for low beam light, the change from low beam light operational mode to high beam light operational mode is solved by means of an additional statical light chamber having halogen light source, or by means of the mechanical movement of the optical element, such as discharge light source, an occulter, a reflector or a part of the reflector, relative to the whole headlamp (see the patent documents U.S. Pat. No. 5,769,525, DE 197 41 377, DE 197 10 632).
The disadvantages of the above mentioned solutions include the use of additional action members, their installation in headlamp, the increased weight of the whole headlamp, the greater susceptibility of the system to failure, and the higher cost of said headlamp.
A further concern occurs when using the discharge light source in the flasher mode, where the service life is decreased as a consequence of repeated switching on.
At the present time this function is solved by means of an additional light chamber, which is also used for high beam light. From this point of view the most advantageous solution for optimization of high beam light operational mode seems to be use of an adjusting action member, which must be part of an automatic adjusting system in a construction having a discharge light source, and use of a horizontal action member to allow horizontal swiveling of low beam light chamber.
This automatic adjusting system comprises sensors for evaluation of the angle of inclination of the vehicle, a control unit for evaluation of input signals from sensors, and an adjusting action member to respond to the control unit.
The adjusting action member provides swiveling of the whole reflector around a pivot fulcrum so as to maintain correct adjustment of the vertical inclination of the low beam boundary, according to the prescribed requirements.
The horizontal adjusting action member allows for a change in the horizontal position of the low beam light chamber for better illumination of the road in curves.